In comparison with procedures that involve extraction,
ashing, and extraction or dry ashing and dissolution
of the ash, the present procedure is straightforward
and simple, with less risk for contamination because the
use of many chemicals, pipettings, and vessels is obviated.
When evaluating several urmnes against one
standard curve, one person can analyze about 30 urine
samples in 8 h, including calculating the results. When
the method of standard addition is used, at least 15
urines may be analyzed in 8 h. This is faster than analysis
after extraction and less elaborate than other procedures
that depend on (e.g.) dry or wet ashing. Our
procedure lends itself to automatization of the injection
by use of an autosampler. Modification of the equipment
is necessary for cadmium in urine, so that a satisfactory
burning out of the graphite tube takes place
after each atomization. This partial automation increases
the rate of analysis and, needless to say, saves
on labor costs.